Electric switch



pr 1931- H. N. BEEBE ELECTRIC SWITCH Filed June 12, 1929 2 Sheets-Sheetln/rntow Hc "old N. Beebe, by 4%,

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April 28, 19 H. N. BEEBE ELECTRIC SWITCH Filed June 12, 1929 2Sheets-Sheet In \fc-zntol" I Harold N. Beebe,

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Patented Apr. 28, 1931 UNITED STATES PATENT OFFICE HAROLD N. BEEBE, OFPITTSFIELD, MASSACHUSETTS, ASSIGNOR T GENERAL ELECTRIC COMPANY, ACORPORATION OF NEW YORK ELECTRIC SWITCH Application filed June 12, 1929.Serial No. 370,206.

In low voltage alternating current distribution systems, the transformerstations at the ends of the feeder cables are located in vaults, thesize of which is restricted by eco- 13 nomic factors and undergroundcongestion.

- Moreover, it is often necessary, particularly in congested districtsto use existing vaults which were not builtto meet the demands of systemchanges and better service. Inas- 1; much as the feeder circuits areoperated at relatively high voltages, ranging from 4,000 to 26,000volts,the necessary insulation in view of the space limitations is of greatimportance especially for switches. If an insulati'ng fluid such as oilis used for the switches, it must not be allowed to escape and therebyaffect the'insulation and create a fire hazard. Because of theprobability of dampness and even flooded conditions of the vaults, watermust'be kept from the switch parts and the insulating fluid. Moreover,in order to insure safety and convenience for testing, operation andmaintenance, the switch apparatus must be safely accessible and ar- 33ranged to prevent improperor dangerous operation.

- It is then an object'of my invention to provide an improvedand simpleswitch which is compact and yet conveniently accessible and which isfluid tight. Another object is to provide an improved switch which issuitably insulated for the desired voltages. A further object is toprovide an improved switch which insures a high degree of safety forboth apparatus and operator under normal operating conditions andparticularly during testing and maintenance.

My invention will be better understood from the following descriptionwhen considered in connection with the accompanying drawings and itsscope will be pointed out in the appended claims.

In the accompanying drawings, Fig. 1 is a front elevation of adouble-throw switch embodying my invention, the switch being shown inone of its circuit closing positions; Fig. 2 is a part sectionalelevation on the line 22 of Fig. 1 with the switch in the same positionas in Fig. 1; Fig. 3 is similar to Fig. 2 except that the switch isshownin the circuit opening position; Fig. 4 is similar to Fig. 2 exceptthat the switchis shown in its other circuit closing position; Figs. 5,6 and 7 are perspective views of a part of the operating mechanism ofthe switch shown in Fig. 1 with the parts positioned to correspond withthe conditions in Figs. 2, 3 and 4 respectively; Fig. 8 is a transversesectional elevation of the operating mechanism with the parts positionedas shown in Fig. 6; Fig. 9 is a perspective view of the switch shown inFig. 1 with parts omitted for the sake of clearness; and Fig. 10 is acircuit diagram illustrating an application of the switch shown in Fig.1.

The embodiment of my invention chosen for the purpose of illustration isa three-phase double-throw switch including two relative sationaryspaced contact means such as front and back contacts 11 and 12respectively and a cooperating movable contact means such as thecontacts 13. The contacts 11 have terminals 14 and are mounted ininsulators 15 supported on a member 16. As shown this member, which maybe of insulating material, extends between the end plates 17. The

contacts 12 may be similarly mounted but in order to use the switch forgroundlng purposes they are shown as mounted on a cross member 18 ofelectric current conducting material. This member is arranged to begrounded through a flexible lead 19 and screw connection 20 to theswitch chamber or housing 21 which is cut away for clearness in showingthe switch parts.

Inasmuch as the usual insulating materials are not well adapted towithstand torsional stresses and to obtain the necessary strength wouldmean undesirable bulk, I provide in accordance with myinvention anarrangement for actuating the movable contacts 13 whereby to insure bothstrength and insulation without bulk. As shown this arrangement includesa contact supporting member 22 which is of insulating material such as ashaft 23 at the ends of a crank or cranks 24 secured thereto. The shaft23 is journalled on .the end plates 17 and may be of any suitablemetallic material for torsion stresses and, if desired, may be providedwith a coating or layer 25 of insulating material for further safety.

In orderto lock the switch in its different circuit controlling;positions, the extension of the shaft 23 through one of the end plates17 may be provided with interlocking means shown as of the bar andsector type, the bar 26 being arranged to be actuated by .suitableelectromagnetic means 27 and to engage slots in the sector 28 which issecured to the shaft. v

In order to control the angular position of the movable contactsupporty22 as the shaft 23 is rota'tedand the contacts 13 are moved froma positionadjacent one set of stationary contacts to a position adjacentthe other set so as to insure proper register with these contacts, Iprovide in accordance with my invention relatively movable guidingelements such as an arm or arms 29 extending from the member 22 andengaging guides 30 on the end plates17, the engagement with theguidesbeing such as to permit the desired angular movement ofthe arms. Forthis purpose the guides may have suitably shaped and enlarged openingsora swivel mounting may be used. The movable contacts 13 are con -nectedthrough flexible leads 31 to entrance also serve'as adjustable membersto tie the end plates together at the bottom, as shown. In order tomount the switch relatively to its" casing for easy withdrawal-andreplacement, the casing and walls 21, as shown in Fig. 1, may beprovided with angle shelves 35. In these are mounted set screws 36 whichengage the end plates 17 or projections thereon so as .to determine theposition of the switch in its casing. Suitable fastening means such asbolts 37 extend through the shelves into theend plates 17. Obviously, onwithdrawal of these bolts, the end plates are movable relatively to thecasing 21 and with the switch in the open position shown in Fig. 3 andupon release of the electrical connec tions including the oundconnection 19, 20; the connections to t 1e terminals 14, the conmotionsof the flexible leads 31 to the bushings 32, and the auxiliary circuitconductors 38 of the electromagnetic locking means 27, the switch bewithdrawn from its casing.

If the adjustment of the set screws 36 is not disturbed, replacement isreadil possible or adjustment can easily be made if necessary to lineupthe witch relatively to its casing.

Further, i accordance with myinvention, I provide a switch operatingmeans 40 whereby the switch may be locked in any of I its circuitcontrolling positions and whereby movement from one circuit closingposition through the open position to the other closed position cannotbemade without some forethought on the part of the operator. The operatingmeans 40 also includes means for maintaining a substantially fluid tightseal about the part of the operating mechanism which projects throughthe casing 21. As shown, the operating. means includes a base 41 whichis secured to the casing 21 by suit- I .any one of its positions, Iprovide a locking member'48 which is pivoted on the base 41 and isprovided with alocking lug 49. In the open position of the switch, thelocking lug 49 is arranged to be entered into a slot 50 in the operatingmember 44 and in either of the closed positions of the switch thelocking lug 49 can be placed in the path of movement of one or t e otherof the lugs 51 on the operating member 44. Looking eyes 52 on the base41 and the locking member 48 come into register when the locking memberis in locking position and a padlock 53 may be inserted to preventunauthorized operation of the switch.

While the shaft portion of the operating member 44 passes throughsuitable packing and a gland bushing54, this must not be so tight as toprevent or make difficult the rotation of the shaft 23 and yet theswitch casing must be maintained fluid tight from both within andwithout I further provide in accordance with my invention for obtainingthis fluid tight seal an arrangement which can he released to permitrotation of the op-. erating 'member 44 when desired and yet maintain aneffective seal at all other times. For this purpose Iprovide anadditional packing means such as a gasket 55 where the shaft portion 45extends through the base 41 arranged so that the locking member 48 ma beoperated to perform not only its loc ing function but also the necessarysealing function as this insures simplicity of the apparatus. For thispurpose the locking member is provided with an eccentric or cam portion56 which engages the outer extremity of the shaft portion 45.- With thelocking member in the position shown in Figs. 5 to 8 inclusive, the camexerts considerable pressure onthe shaft portion 45 thereby compressingthe packing 55 around the shaft.

Upon counter-clockwise rotation of the lockthe movement of the operatingmember 44 fromone of the circuit closing positions as shown in Fig. 5 tothe circuit open position shown in Fig. 6, whereby the operating membercannot be moved to the other cir cuit closing position shown in Fig. 7without returning from the circuit open position to the circuit closedposition shown in Fig. 5 and performing in this position a specialoperation. As shown, this motion limiting means includes a lockingelement 57 pivotaily associated with the operating member 44 at 58. Thelocking element 57 carries at its other end a projection such as a pin59 which projects through the slot 50 in the operating member into acooperating interlocking element such as the slot 60 in a raised portionof the base 41. This slot 60 is open atone end and closed at the otherend and of such length as to permit the illustrated embodiment of myinvention substantially a 90 movement of the operating member as will bemore clearv 1y apparent from Fig. 7, that is from the position shown inFig. '5 to the position shown in Fig. 6. In order to permit therereleasing movement of the member 57, the end pivoted to the operatingmember 44 includes a lost motion slot. The open end of the slot 60 issuch that the pin 59 in the limiting link 57 can be withdrawn from theslot 60 by movement in the slot of the op crating member 44 only whenthe operating member 44 is in the position shown in Fig. 5. This is theposition corresponding to engage? ment of the contacts 13 with thecontacts 11.

In the schematic circuit arrangement shown in Fig. 10 to illustrate anapplication of a switch embodying my invention,-a polyphase high voltagefeeder 61 is connected to a low voltage network 62 through the contacts11, 13 of a switch suchas shown in Fig. .1, a step down transformer 63and a circuit breaker 64. The electromagnetic inter.- locking means 27may be connected across a phase of the network as shown, so thatwhenever the circuit breaker 64 is closed and the network is energized,or the feeder is energized, the electromagnet 27 wili be excited to lockthe switch sector 28 so as to prevent operation of the switch 11, 13 ona 'iive circuit.

This insures the operators safety since it is thus impossible to openthe disconnecting switch 11, 13'under load.

1 Assuming that the feeder disconnecting switch is in the circuitclosing position, that is, that the contacts 11 and 13are in engagementand that the circuit breaker 64 is closed and either the feeder 61 orthenetwork 62 or both are energized, it will be impossible to turn theswitch since the electromagnetic means 27 is energized and engages theinterlocking sector 28. Under these conditions the switch parts arepositioned as shown in Figs. 1, 2, 5 and 9. If for any reason it isdesired to work on any of the equipment in the vault or chambercontaining the transformer 63 the circuit breaker 62 and thedisconnecting switch, the operator must first arrange to have the feedercircuit 61 opened, for example, at the power 'station and must eifectthe opening of the circuit breaker 64. The electromagnetic means 27 isthus deenergized and the locking sector 28 released. Whoever isauthorized may unlock the padlock ,53 thus unlocking the operatingmechanism 40. Even though this mechanism were not unlocked prior to theopening of the circuit breaker 6'4 and the feeder circuit 61, it wouldstill be impossible to move the operating handle since the interlockingmeans 26, 27 and 28 would be engaged. Assuming, however, that thisinterlocking means is released, then the operating handle 44 can bemoved into the circuit open position shown in Fig. 6 aftercounter-clockwise movement of the locking element. 48 whichm'oves thelug 49 out of the path of movement of the lug 51 as will be obvious fromFig. 5, and releases the pressure on the packing 55. The operatinghandle 44 'may'then be moved into the position shown in Fig. 6, and, ifdesired, locked in this position by turning the locking element 48clockwise into the position shown in Figs. 6 and 8 with the locking lug49 in the slot 50 on the operating handle 44. In this position thepadlock 53 may again be inserted in the registering eyes 52 if it isdesired to lock the switch against unauthorized use.

If the switch is moved to the open position shown in Figs. 3, 6 and 8,and left in this position with the locking element 48 in the lockingposition with pressure on the packing 55, it may be that an operator ormaintenance man might come along and release the member 48 and try tomove the operating handie to the ground position. This, of course,cannot be done if the electromagnetic interlock 27 is energized. If,however, the switch is in the open position and the circuit breaker 64is open and in the meantime the feeder 61 has been energized for exampleby closing the switch the power station, then the interlocking means 27would be deenergized and if the operating member 44 could be moved tothe ground position a polyphase I ice short circuit would be put on thelive feeder 61. This, of course, must not be'done. If under theseconditions the operator attempts to more the contacts 13 to the groundposition he will find it impossible to do so since the pin 59 in thelink 57 comes to the closed end of the slot 60 when the operating member44 is in the switch open position. Consequently, the operating handlemust be moved from the open position back to the closed position shownin Fig. 5 before the pin 59 can be released from the slot 60. However,when the operator makes this closing movement of the operating member44-if the feeder 61 is energized the electromagnetic interlock 27 willbe excited even though the circuit breaker 64 is open. Consequently, assoon as the switch is returned to the closed position it will be lockedthere by the electromagnetic interlock and the operator will be unableto move it from this position. If, however, the feeder 61 were notenergized and the circuit breaker 64 were open when this return movementto iheclosing position is made, the operating handle would be free formovement to the ground position upon n'ioving'the link 57 so that itspin 59 moves outward in the slot 50 and away from the slot 60. Theoperating handle may then be moved substantially 180 to the positionshown in Fig.7., This is the grounding position of the switch with thecontacts 12 and 13 in engagement, as shown in Fig. 4. In this positionof the switch the return of the locking element 48 to the position shownin Fig. 7 restores the pressure about the shaft extension 45 and putsthe lug 49 in the path of movement of the lug 51 on the operating member44, and if desired, the switch may be locked in this position byinserting the padlock in the eyes 52. Upon the release of the lockinglever 48, theswitch can be returned from the ground'position to the openposition, but cannot be locked in this position since the link 57 willbe in the path of movement of the lug 49. This will be apparent from 8,for the pin 59 will be in the lug 65 in line with the lug 49. In orderto lockthe switch in the open position the operating member 44 must bereturned to the closed position, as shown in Fig. 5, where the pin 59will automatically-engage the slot 60. This automatic return is due togravity when the operating mechanism is mounted as shown in Fig. 1, butit will be apparent that any other suitable biasing means could beemployed.

lVhile Ihave shown and described my invention in considerable detail, Ido not deire to be limited to the exact arrangements shown but seek tocover in the appended claims all those modificaions thatfall within thetrue spirit and scope of my invention.

VVh-at I claim as new and desire to secure by Letters Patent of theUnited States is 1. An electric switch including relatively movablecontact means and actuating means therefor including an operating membermovable to a plurality of positions and means for permitting a limitedmovement of said member from one'of said positions including a lockingelement mounted on said member for movement relatively thereto, saidelement being releasable only when the member is in said oneof saidpositions to permit a greater movement of the member.

2. An electric switch including relatively movable contact means andactuating means therefor including an operating member movable to aplurality of positions and means for permitting a limited movementot'said member from one of said positions including relatively movableinterlocking elements rcleasable only when the member is in said one ofsaid positions to permit a greater movement of the member. 3. Anelectr1c switch mcludmg two relatively stationary spaced contacts, acooperating movable contact, and actuating means therefor including arotatable operating member, an insulating support for said movablecontact pivotally mounted on said operating member and relativelymovable guiding elements for controlling the angular po sition of saidsupport on rotation of said operating member to actuate the movablecontact from a position adjacent one of the stationary contacts to aposition adjacent the other stationary contact, one of said elementsbeing secured to said support.

4. An electric switch including relatively movable cooperating contactsand actuating means therefor includinga rotatably mounted operatingmember, an insulating member for supporting one of said cont-actspivotally mounted on said operating member and relatively movable meansfor controlling the angular position of the insulating member.

5. In an electric switch having relatively movable contacts mounted in achamber, switch operating means including a member extending into thechamber, and means for maintaining a substantially fluid tight svalabout said member arranged to be actuated to scaling position when themember is in a predetermined position and when in the sealing positionto prevent the movement of the member. 1

6. An electric switch including relatively movable contacts andactuating means therefor including an operating member movable to aplurality of positions, means for permitting a limited movement of saidmember from one of said positions releasable when the member is in saidone of said positions to permit a greater movement of the member andmeans adapted to be operated when the member is in any one oi saidpositions to lock the member against movement.

7. An electric switch including two relatively stationary contact meansand a fnovable contact means arranged to be positioned to engage eitherof said stationary contact means, means for actuating the movablecontact means including an operating member arranged on movement in onedirection to disengage the movable contact means from one of thestationary contact means, means for limiting the movement of theoperating member in said direction whereby to prevent engagement of themovable contact means with the other stationary contact means,releasable to permit sai "engagement only when the movable contact meansis in engagement with said one of said contact means.

8. An electric switch including two relatively stationary spaced contactmeans, a cooperating movable contact means, and actuating means thereforincluding ashaftmounted between said stationary contact means, a crankon said shaft, an insulating support for said movable contact meanspivotally mounted on said crank whereby on a predetermined rotation ofsaid shaft the movable contact means is moved from a position adj acentone stationary contact means to a position adjacent the other stationarycontact means, and means for controlling the angular position of saidsupport including an arm extending from the support and a guide for thearm.

9. An electric switch including two rela--- .means inqlud'ing ,a memberextending into the fiuid containing chamber and movable to a pluralityof positions, means for permitting a limited movementof said member fromone of said positions releasable when the member is in said positions topermit agreater movement of the member, and means for maintaining asubstantially fluid tight seal about said member arranged to be actuatedto sealing position when the member 'is in one of sad positions andwhenin the sealing position to prevent movement of the member.

11. An electric switch including relatively movable contact means andactuating means therefor including an operating. member movable to aplurality of positions and means for permitting a limited movement ofsaid member from one of said positions including relatively movableelements respectively provided with a slot and a projection mounted formovement in the slot, said projection being removable from said slotonly when the operating member is in a predetermined position to permita greater movement of the member.

12. An electric switch including relatively movable contact means andactuating means therefor including an operating member mov- In Witnesswhereof I have hereunto set my hand this 10th day of June, 1929.

' HAROLD N. BEEBE.

CER'liFiCA'lE @F CORRECTION.

Patent No. 1,803,163. Granted April 28, 1931, to

HAROLD N. BEEBE.

It is hereby certified that error appears in the printed specificationof the above numbered patent requiring correction as follows: Page 5,line 51, claim 10, before "positions" insert the words one of said; andthat the said Letters Patent should be read with this correction thereinthat the same may conform to the record of the case in the PatentOffice.

Signed and sealed this 2nd day of June, A. l). 1931.

M. J. Moore, (Seal) Acting Commissioner of Patents.

